1. Field of the Invention
The present invention relates to an air conditioner in which a desiccant air conditioner is combined with a refrigerating device having a refrigeration cycle provided with a compressor and the like.
2. Description of the Related Art
Heretofore, an air conditioner is known in which a desiccant air conditioner is combined with a refrigeration cycle provided with a compressor and the like. For example, in Japanese Patent Application Laid-Open No. 2004-85096, there is disclosed an air conditioner constituted by combining the desiccant air conditioner, a device involving exhaust heat from a gas engine or the like, and a refrigerating device having the refrigeration cycle. This air conditioner is constituted as shown in FIG. 5. It is to be noted that in FIG. 5, a solid-line arrow shows a flow of outside air (hereinafter referred to as supply air) taken into a room from the outside, and a broken-line arrow shows indoor air (hereinafter referred to as indoor exhaust air) discharged from the room to the outside.
As shown in FIG. 5, an air conditioner 100 includes: a desiccant air conditioner 120 including a supply air passage 3 which introduces outside air into a room 2 and an exhaust air passage 4 which discharges indoor air; and a refrigerating device 110. Moreover, the supply air passage 3 is disposed adjacent to the exhaust air passage 4.
The refrigerating device 110 includes a compressor 65, a driving source 63 as a driving element of the compressor 65, a heater 12, an expansion valve 14, an evaporator 15, and an exhaust heat heater 64 which utilizes exhaust heat of the driving source 63. They are successively connected to one another to form the refrigeration cycle.
In the supply air passage 3, there are successively arranged a supply air passage section of a rotary dehumidifier 5, a supply air passage section of a rotary sensible heat exchanger 6, and the evaporator 15 from the outdoors toward the interior of the room 2. On the other hand, in the exhaust air passage 4, there are successively arranged a eveporative cooler 8, an exhaust air passage section of the rotary sensible heat exchanger 6, the heater 12, the exhaust heat heater 64, and an exhaust air passage section of the rotary dehumidifier 5 from the room 2 toward the outdoors.
As shown in FIG. 5, the rotary dehumidifier 5 is disposed ranging from the supply air passage 3 to the adjacent exhaust air passage 4. Accordingly, the supply air passage section is disposed on the side of the supply air passage 3, and the exhaust air passage section is disposed on the side of the exhaust air passage 4 as described above. This rotary dehumidifier 5 adsorbs moisture from passing supply air to dehumidify the supply air passage section in the supply air passage 3. In the exhaust air passage section of the exhaust air passage 4, an adsorbing section which has adsorbed the moisture is heated, dried, and regenerated by passing high-temperature indoor exhaust air heated by the heater 12 and the like.
The rotary sensible heat exchanger 6 is a rotary heat exchange rotor. Moreover, this rotary sensible heat exchanger 6 is constituted to allow supply air passing through the supply air passage section of the supply air passage 3 to exchange sensible heat with indoor exhaust air passing through the exhaust air passage section of the exhaust air passage 4.
In the evaporator 15, a refrigerant whose pressure has been reduced by the expansion valve 14 evaporates to absorb heat from its periphery, and the evaporator further cools supply air cooled by the supply air passage section of the rotary sensible heat exchanger 6.
Moreover, in the heater 12, a high-temperature high-pressure refrigerant compressed by the compressor 65 radiates heat to heat the periphery, and the heater further heats indoor exhaust air heated by the exhaust air passage section of the rotary sensible heat exchanger 6. Furthermore, after the indoor exhaust air heated by the heater 12 is further heated by the exhaust heat heater 64, indoor exhaust air reaches the exhaust air passage section of the rotary dehumidifier 5.
It is to be noted that the humidifier 8 sprays water such as city water to cool indoor exhaust air.
Next, there will be described a function of the air conditioner 100 constituted as described above. First, outdoor air, that is, supply air is conveyed into the rotary dehumidifier 5 via the supply air passage 3. Moreover, supply air is dehumidified in the supply air passage section of the rotary dehumidifier 5. At this time, heat of adsorption is generated in this supply air passage section.
Furthermore, after supply air dehumidified as described above is cooled by indoor exhaust air flowing into the exhaust air passage section of the rotary sensible heat exchanger in the supply air passage section of the rotary sensible heat exchanger 6, supply air is further cooled by the evaporator 15, and supplied into the room 2.
On the other hand, indoor exhaust air is first humidified in the eveporative cooler 8, and cooled by latent heat of evaporation of water. Thereafter, indoor exhaust air is heated by heat of supply air flowing into the supply air passage section of the rotary sensible heat exchanger 6 in the exhaust air passage section of the rotary sensible heat exchanger 6. Moreover, after indoor exhaust air is heated in the heater 12, indoor exhaust air is further heated by the exhaust heat heater 64. Thereafter, indoor exhaust air heats and dries an adsorbent in the exhaust air passage section of the rotary dehumidifier 5, and indoor exhaust air itself is humidified and discharged to the outdoors.
Here, there will be described an enthalpy and pressure graph of the refrigeration cycle in the refrigerating device 110 of the air conditioner 100 with reference to FIG. 2. In FIG. 2, cycle graphs shown by broken lines, that is, (1), (2), (6), and (5) show refrigeration cycle graphs in this case. In this case, the refrigerant circulates in order of (1) suction of the compressor 65, (2) discharge of the compressor 65, (6) an outlet of the heater 12, (5) an outlet of the expansion valve 14 corresponding to an inlet of the evaporator 15, and (1) suction of the compressor 65 to thereby form the refrigeration cycle
In the air conditioner 100 described above, since indoor exhaust air heated by the heater 12 is further heated by the exhaust heat heater 64, temperature rises in the other half of the rotary dehumidifier 5 in the exhaust air passage 4. Therefore, temperature of supply air passing through the supply air passage section of the rotary dehumidifier 5 rises. Moreover, temperature in the rotary sensible heat exchanger 6 also rises. Therefore, this air conditioner 100 is constituted so that indoor exhaust air is cooled by the eveporative cooler 8 to lower the temperature of the rotary sensible heat exchanger 6.
However, the eveporative cooler 8 is required for the above-described constitution. Even if such eveporative cooler 8 is disposed, the temperature of the refrigerant discharged from the heater 12 also becomes high because the temperature of indoor exhaust air flowing into the heater 12 is high. As a result, a cooling capacity (between (5) and (1) in the cycle graphs shown by the broken lines in FIG. 2) in the evaporator 15 becomes very small. Accordingly, there is a problem that the cooling capacity of supply air into the room degrades, and an energy efficiency in the whole air conditioner lowers.